Fears downpour could spark more mine flooding

The Environment Protection Authority (EPA) says there is still a risk that heavy rain will cause the Yallourn mine to flood.

The Yallourn mine flooded in June when the banks of the Morwell River diversion burst and sent billions of litres of water gushing into the mine.

Energy Australia has been pumping water into the river since the river diversion broke.

Weekly water quality tests indicate that pollution levels in the river continue to fall.

The EPA's Gippsland manager, Dieter Melzer, says another downpour could cause more water to spill into the mine and also increase the amount of water that needs to be pumped into the Latrobe River.

"The concern remains that if we get a heavy large rain event that it could still exceed the capacity of what's been pumped to the river from the bed of the Morwell River and that some of it might spill into the mine as it has done on a number of occasions during the winter," he said.

But he says without rain, the work is likely to be finished before the EPA issued emergency discharge licence expires in February.

"From the information I've received from the company they'll be finished pumping before the expiry of that approval," he said.